add u8g.fb_rle display

This commit is contained in:
devsaurus 2016-09-20 23:37:13 +02:00
parent 19f80abb32
commit 492ee578ae
5 changed files with 250 additions and 14 deletions

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@ -75,6 +75,10 @@
U8G_DISPLAY_TABLE_ENTRY(ssd1306_128x64_hw_spi) \
#undef U8G_DISPLAY_TABLE_ENTRY
// Special display device to provide run-length encoded framebuffer contents
// to a Lua callback:
#define U8G_DISPLAY_FB_RLE
//
// ***************************************************************************

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@ -2,24 +2,14 @@
#include "module.h"
#include "lauxlib.h"
#include "lmem.h"
#include "platform.h"
#include "c_stdlib.h"
#include "u8g.h"
#include "u8g_glue.h"
#include "u8g_config.h"
struct _lu8g_userdata_t
{
u8g_t u8g;
};
typedef struct _lu8g_userdata_t lu8g_userdata_t;
// shorthand macro for the u8g structure inside the userdata
#define LU8G (&(lud->u8g))
// helper function: retrieve and check userdata argument
static lu8g_userdata_t *get_lud( lua_State *L )
@ -986,8 +976,6 @@ uint8_t u8g_com_esp8266_ssd_i2c_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, voi
}
// device destructor
static int lu8g_close_display( lua_State *L )
{
@ -996,6 +984,19 @@ static int lu8g_close_display( lua_State *L )
if ((lud = get_lud( L )) == NULL)
return 0;
if (lud->cb_ref != LUA_NOREF) {
// this is the fb_rle device
u8g_dev_t *fb_dev = LU8G->dev;
u8g_pb_t *fb_dev_pb = (u8g_pb_t *)(fb_dev->dev_mem);
uint8_t *fb_dev_buf = fb_dev_pb->buf;
luaM_free( L, fb_dev_buf );
luaM_free( L, fb_dev_pb );
luaM_free( L, fb_dev );
luaL_unref( L, lud->cb_ref, LUA_REGISTRYINDEX );
}
return 0;
}
@ -1016,6 +1017,7 @@ static int lu8g_close_display( lua_State *L )
return luaL_error( L, "i2c address required" ); \
\
lu8g_userdata_t *lud = (lu8g_userdata_t *) lua_newuserdata( L, sizeof( lu8g_userdata_t ) ); \
lud->cb_ref = LUA_NOREF; \
\
lud->u8g.i2c_addr = (uint8_t)addr; \
lud->u8g.use_delay = del > 0 ? 1 : 0; \
@ -1049,6 +1051,7 @@ U8G_DISPLAY_TABLE_I2C
unsigned del = luaL_optinteger( L, 4, 0 ); \
\
lu8g_userdata_t *lud = (lu8g_userdata_t *) lua_newuserdata( L, sizeof( lu8g_userdata_t ) ); \
lud->cb_ref = LUA_NOREF; \
\
lud->u8g.use_delay = del > 0 ? 1 : 0; \
\
@ -1064,6 +1067,53 @@ U8G_DISPLAY_TABLE_I2C
// Unroll the display table and insert binding functions for SPI based displays.
U8G_DISPLAY_TABLE_SPI
//
//
//
// This display forwards the framebuffer contents as run-length encoded chunks to a Lua callback
static int lu8g_fb_rle( lua_State *L ) {
lu8g_userdata_t *lud;
if ((lua_type( L, 1 ) != LUA_TFUNCTION) &&
(lua_type( L, 1 ) != LUA_TLIGHTFUNCTION)) {
luaL_typerror( L, 1, "function" );
}
int width = luaL_checkint( L, 2 );
int height = luaL_checkint( L, 3 );
luaL_argcheck( L, (width > 0) && (width < 256) && ((width % 8) == 0), 2, "invalid width" );
luaL_argcheck( L, (height > 0) && (height < 256) && ((height % 8) == 0), 3, "invalid height" );
// construct display device structures manually because width and height are configurable
uint8_t *fb_dev_buf = (uint8_t *)luaM_malloc( L, width );
u8g_pb_t *fb_dev_pb = (u8g_pb_t *)luaM_malloc( L, sizeof( u8g_pb_t ) );
fb_dev_pb->p.page_height = 8;
fb_dev_pb->p.total_height = height;
fb_dev_pb->p.page_y0 = 0;
fb_dev_pb->p.page_y1 = 0;
fb_dev_pb->p.page = 0;
fb_dev_pb->width = width;
fb_dev_pb->buf = fb_dev_buf;
u8g_dev_t *fb_dev = (u8g_dev_t *)luaM_malloc( L, sizeof( u8g_dev_t ) );
fb_dev->dev_fn = u8g_dev_gen_fb_fn;
fb_dev->dev_mem = fb_dev_pb;
fb_dev->com_fn = u8g_com_esp8266_fbrle_fn;
lud = (lu8g_userdata_t *) lua_newuserdata( L, sizeof( lu8g_userdata_t ) );
lua_pushvalue( L, 1 ); // copy argument (func) to the top of stack
lud->cb_ref = luaL_ref( L, LUA_REGISTRYINDEX );
/* set metatable for userdata */
luaL_getmetatable(L, "u8g.display");
lua_setmetatable(L, -2);
u8g_Init8BitFixedPort( LU8G, fb_dev, width, height, 0, 0, 0);
return 1;
}
//
// ***************************************************************************
@ -1137,6 +1187,8 @@ static const LUA_REG_TYPE lu8g_map[] = {
#define U8G_FONT_TABLE_ENTRY(font) \
{ LSTRKEY( #font ), LUDATA( (void *)(u8g_ ## font) ) },
U8G_FONT_TABLE
//
{ LSTRKEY( "fb_rle" ), LFUNCVAL( lu8g_fb_rle ) },
// Options for circle/ ellipse drawing
{ LSTRKEY( "DRAW_UPPER_RIGHT" ), LNUMVAL( U8G_DRAW_UPPER_RIGHT ) },
{ LSTRKEY( "DRAW_UPPER_LEFT" ), LNUMVAL( U8G_DRAW_UPPER_LEFT ) },

136
app/modules/u8g_glue.c Normal file
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@ -0,0 +1,136 @@
/*
Functions for integrating U8glib into the nodemcu platform.
*/
#include "lauxlib.h"
#include "c_stdlib.h"
#include "u8g.h"
#include "u8g_glue.h"
// ***************************************************************************
// Generic framebuffer device and RLE comm driver
//
uint8_t u8g_dev_gen_fb_fn(u8g_t *u8g, u8g_dev_t *dev, uint8_t msg, void *arg)
{
switch(msg)
{
case U8G_DEV_MSG_PAGE_FIRST:
// tell comm driver to start new framebuffer
u8g_SetChipSelect(u8g, dev, 1);
break;
case U8G_DEV_MSG_PAGE_NEXT:
{
u8g_pb_t *pb = (u8g_pb_t *)(dev->dev_mem);
if ( u8g_pb_WriteBuffer(pb, u8g, dev) == 0 )
return 0;
}
break;
}
return u8g_dev_pb8v1_base_fn(u8g, dev, msg, arg);
}
static int bit_at( uint8_t *buf, int line, int x )
{
uint8_t byte = buf[x];
return buf[x] & (1 << line) ? 1 : 0;
}
struct _lu8g_fbrle_item
{
uint8_t start_x;
uint8_t len;
};
struct _lu8g_fbrle_line
{
uint8_t num_valid;
struct _lu8g_fbrle_item items[0];
};
uint8_t u8g_com_esp8266_fbrle_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr)
{
struct _lu8g_userdata_t *lud = (struct _lu8g_userdata_t *)u8g;
switch(msg)
{
case U8G_COM_MSG_INIT:
// allocate memory -> done
// init buffer
break;
case U8G_COM_MSG_CHIP_SELECT:
if (arg_val == 1) {
// new frame starts
if (lud->cb_ref != LUA_NOREF) {
// fire callback with nil argument
lua_State *L = lua_getstate();
lua_rawgeti( L, LUA_REGISTRYINDEX, lud->cb_ref );
lua_pushnil( L );
lua_call( L, 1, 0 );
}
}
break;
case U8G_COM_MSG_WRITE_SEQ:
case U8G_COM_MSG_WRITE_SEQ_P:
{
uint8_t xwidth = u8g->pin_list[U8G_PI_EN];
size_t fbrle_line_size = sizeof( struct _lu8g_fbrle_line ) + sizeof( struct _lu8g_fbrle_item ) * (xwidth/2);
int num_lines = arg_val / (xwidth/8);
uint8_t *buf = (uint8_t *)arg_ptr;
struct _lu8g_fbrle_line *fbrle_line;
if (!(fbrle_line = (struct _lu8g_fbrle_line *)c_malloc( fbrle_line_size ))) {
break;
}
for (int line = 0; line < num_lines; line++) {
int start_run = -1;
fbrle_line->num_valid = 0;
for (int x = 0; x < xwidth; x++) {
if (bit_at( buf, line, x ) == 0) {
if (start_run >= 0) {
// inside run, end it and enter result
fbrle_line->items[fbrle_line->num_valid].start_x = start_run;
fbrle_line->items[fbrle_line->num_valid++].len = x - start_run;
//NODE_ERR( " line: %d x: %d len: %d\n", line, start_run, x - start_run );
start_run = -1;
}
} else {
if (start_run < 0) {
// outside run, start it
start_run = x;
}
}
if (fbrle_line->num_valid >= xwidth/2) break;
}
// active run?
if (start_run >= 0 && fbrle_line->num_valid < xwidth/2) {
fbrle_line->items[fbrle_line->num_valid].start_x = start_run;
fbrle_line->items[fbrle_line->num_valid++].len = xwidth - start_run;
}
// line done, trigger callback
if (lud->cb_ref != LUA_NOREF) {
lua_State *L = lua_getstate();
lua_rawgeti( L, LUA_REGISTRYINDEX, lud->cb_ref );
lua_pushlstring( L, (const char *)fbrle_line, fbrle_line_size );
lua_call( L, 1, 0 );
}
}
c_free( fbrle_line );
}
break;
}
return 1;
}

20
app/modules/u8g_glue.h Normal file
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@ -0,0 +1,20 @@
#ifndef _U8G_GLUE_H_
#define _U8G_GLUE_H_
#include "u8g.h"
struct _lu8g_userdata_t
{
u8g_t u8g;
int cb_ref;
};
typedef struct _lu8g_userdata_t lu8g_userdata_t;
// shorthand macro for the u8g structure inside the userdata
#define LU8G (&(lud->u8g))
uint8_t u8g_com_esp8266_fbrle_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr);
uint8_t u8g_dev_gen_fb_fn(u8g_t *u8g, u8g_dev_t *dev, uint8_t msg, void *arg);
#endif

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@ -202,6 +202,30 @@ disp = u8g.ssd1306_128x64_hw_spi(cs, dc, res)
#### See also
[I²C Display Drivers](#i2c-display-drivers)
## u8g.fb_rle
Initialize a virtual display that provides run-length encoded framebuffer contents to a Lua callback.
The callback function can be used to process the framebuffer line by line. It's called with either `nil` as parameter to indicate the start of a new frame or with a string containing a line of the framebuffer with run-length encoding. First byte in the string specifies how many pairs of (x, len) follow, while each pair defines the start (leftmost x-coordinate) and length of a sequence of lit pixels. All other pixels in the line are dark.
```lua
n = struct.unpack("B", rle_line)
print(n.." pairs")
for i = 0,n-1 do
print(string.format(" x: %d len: %d", struct.unpack("BB", rle_line, 1+1 + i*2)))
end
```
#### Syntax
`u8g.fb_rle(cb_fn, width, height)`
#### Parameters
- `cb_fn([rle_line])` callback function. `rle_line` is a string containing a run-length encoded framebuffer line, or `nil` to indicate start of frame.
- `width` of display. Must be a multiple of 8, less than or equal to 248.
- `height` of display. Must be a multiple of 8, less than or equal to 248.
#### Returns
u8g display object
___
## Constants